pipe jacking, microtunnelling, & auger boring - nodig-construction.com

PIPE JACKING, MICROTUNNELLING, 

& AUGER BORING 

For General Information on Pipe Jacking, Microtunnelling & Auger Boring click here 

CURVED PIPE JACKED DRIVES BRING FLOOD RELIEF TO SIDCUP 

n Longlands Road in Sidcup, Kent, UK the 

O basements of some 20 properties are at risk of 

foul water flooding given the right circumstances. 

Being in the area of responsibility covered by 

Thames Water, the properties were originally served 

by an existing foul sewer that needed to be 

reconstructed and the network expanded to alleviate 

this flooding risk. Thames Water decided to establish 

a project to complete an upgrade of the existing 

sewer network and to install a storage tank as well as 

additional manholes and realignment of certain 

collector flows. The new storage tank was designed 

with a capacity to handle flows generated by a 

30-year return period storm. The project is known as 

Main Road, Sidcup FWFAS 

Re-installation, construction and realignment of the 

majority of the network flows was to be undertaken 

by the main contractor appointed for the works, Dean 

& Dyball, with much of the works being completed 

in open cut. However, approximately 60 m of auger 

boring along was required along with the 

construction of the new storage tank facility to A view along one of the curved Sidcup 

complete the new sewer network. The tank facility pipe jacked storage tank drives from the 

required the installation of a completely new 1,800 launch cofferdam looking through the 

mm diameter pipeline over a length of some 197.5 m. shove ring and over the muck skip. 

It was decided that pipe jacking techniques were most 

suited to this part of the works. This part of the project was sub-contracted to A.E. Yates Trenchless 

Solutions Ltd (AE Yates TS), a contractor with specialist knowledge of and experience in the 

application of trenchless technology solutions. 

PIPE JACKING WORKS 

The ground conditions that were expected to be encountered over the length of the storage tank 

drives comprised mainly clay with sand veins and some sands and gravels. Having experienced 

similar ground conditions on other drives over its years in the industry, A.E. Yates TS opted to 

utilise an open face backacter tunnelling unit for the excavation work. In this instance the company 

chose to use a 1,800 mm i.d., hydraulic drive Herrenkneckt MH3 – Open faced backacter unit. 

To utilise this machine A E Yates TS was required to sink an 8 m by 4 m cofferdam (designated as 

MRS5) from which two drives were to be installed. The first drive was approximately 97.5 m long 

and included a right hand curve of 375 m radius. The second drive, with a 395 m radius left hand 

curve was approximately 100 m in length. The pipeline, which was to be jacked into place behind 

the tunnelling unit, was to comprise Macrete-manufactured 1,800 mm i.d. concrete jacking pipe 

with 316 stainless steel bands at the joints. Both drives ran at a depth of around 3.5m below road 

level. 

The jacking frame comprised four main hydraulic jacks each with 300 t jacking force capacity, 

which was manufactured by A E Yates TS using Herrenknecht Rams. 

Whilst the installation was not expected to be 

the most difficult of drives, given the 

proximity to local residents, prevailing 

ground conditions and depth, and with both 

drives being curved, a sophisticated guidance 

system was required to ensure the drive 

alignment remained correct. This guidance 

system was hired for the project from 

specialist guidance system manufacturer, 

Germany-based VMT. 

The gyro unit is situated behind the 

tunnelling machine operator position, with 

the control screen located above the driver. 

SPONSORS LINKS 

Click Name for website access 

Insituform 

Technologies Ltd 

Manufacturer and contractor 

for Gravity & Pressure & 

Lateral Pipe Renovation & 

repair (inc CIPP, Close Fit PE 

& Localised Lining), GRP 

Lining, Surveying & Cleaning, 

Manhole Construction & 

Renovation, Pipe bursting and 

Guided Auger Boring. 

TT Group 

TT-Group: A leading 

manufacturer of Trenchless 

Technologies: Moles, Pipe 

Rammers, HDD, Pipe 

Replacement and Auger boring 

systems and NoDig-equipment 

U Mole 

Part of Vp plc 

Suppliers for hire or sale 

of: Vac Ex, Moles & 

Rammers, Bursting, 

Coil Trailers, SBUs 

and Accessories. 

VMT GmbH 

Supplier of TBM, Microtunnel, 

Pipe Jacking and Tunnel 

excavation Navigation & 

Guidance systems & Services. 

Herrenknecht 

Manufacturer of TBMs, 

Pipejacking, Microtunnelling, 

HDD and Support Equipment 

and Engineering Services. 

Perforator Ltd 

Sales and Hire of Guided 

Auger boring and Pipebursting 

systems and tooling. 

To First Page ▲ 

© 2008 NoDig Media Services




GUIDANCE SYSTEM 

The VMT navigation system used for 

the storage tank drives was an SLS 

Microtunnelling G. The SLS-G is a 

gyro based navigation system which 

operates in combination with an 

electronic hose levelling system, which 

was developed for works in small 

diameter bores and situations where 

there was a complex-design tunnel axis. 

The system works so that at any time 

the exact position of the TBM and the 

deviations from the designed tunnel 

axis, as well as the predicted movement 

tendency of the TBM are available to 

the machine operator. The gyro 

A schematic of the VMT-supplied SLS-G navigation 

system used on the Sidcup works to ensure the curved 

drives followed the required tunnel axis. 

compass provides the horizontal position and direction of the TBM, whilst the hose level determines 

the precise height of TBM. 

All components of the system are compact to install and there is no requirement to have a ‘line of 

sight’ connection between them. The influences of refraction which can affect some other types of 

guidance systems do not occur within the measurements taken using the SLS-G system. 

The hardware comprising the SLS-G system is robust and tunnel-proven over many years of use in 

the industry. It is easy to handle and utilises user-friendly software with a permanent recording 

facility for all important drive data. This allows operators to quickly become familiar with the 

handling of the system. 

The information high content of the displayed data ensures an optimum control of the machine 

position in order to keep deviations from the designed tunnel axis to a minimum. The system also 

provides the machine operator with a constant display of the position, orientation and tendencies of 

the machine. The precision of each of these factors means that vertical (if required) and horizontal 

curves can easily be achieved. Furthermore the system provides a complete and permanent 

recording of all geometric advance data for future documentation. 

For the Sidcup operation, the SLS-G system was supplied together with a VMT specialist 

guidance engineer. 

INSTALLATION 

With the cofferdam sunk (amongst existing services), the pipe jacking rig in place and the tunnelling 

machine in position the first drive commenced. 

To ensure that the installation ran as smoothly as possible the pipe jacking operation utilised 

bentonite injection along the pipe chain to lubricate the pipe and minimise friction between the pipes 

and the surrounding ground. The bentonite materials were provided by Baroid IDP with the 

lubricating slurry being delivered to the pipe chain using a standard bentonite mixing and pumping 

system. The lubricating mix flows were manually adjusted injected into the pipe annulus at every 

fourth pipe. 

A.E. Yates TS contacted BAROID IDP to design a lubrication slurry appropriate for the ground 

conditions for the project. Based on the information provided from borehole logs along the line of 

the drive, the lubrication slurry mix 

formulated comprised BORE-GEL sodium 

Wyoming bentonite, with EZ-MUD 

GOLD, a unique beaded readily dispersible 

anionic polymer. Information from tests 

indicated that the ground water was slightly 

acidic having a pH around 6. To counteract 

the detrimental affects of low pH on the 

bentonite and polymer additives, Sodium 

Carbonate was added to the slurry mix 

water. As the first drive approached the exit 

shaft the ground conditions became less 

The surface setup at the start shaft for 

the Sidcup curved drives. 



Insituform 











TT Group 







U Mole 







VMT GmbH 





Herrenknecht 














stable and more porous, 

therefore N-SEAL, a fibrous inert 

mineral additive was 

included in the slurry mix to 

minimise loss to the ground and 

promote stability around the pipe. 

As the installation progressed 

and the face was excavated by 

the Herrenknecht MH3 unit, the 

spoil generated was 

removed from the face by the 

backacter. The spoil was then 

pulled up onto a conveyor which 

passed it into a ‘roll over’ skip. 

Winches were used to pull the 

track-mounted skip into and out 

of the pipe jack. At shaft bottom, 

the skip was lifted out of the cofferdam 

with a lifting beam and 

emptied into the back of a trailer 

pulled by a tractor. Access to the trailer was via a purpose made scaffold platform. The spoil was 

then taken to a designated loading point 500 m from the work site where it could be loaded onto 8 

wheeled tipper trucks for final removal from site. 

In advance of the project and during the course of the works a number of public relations 

requirements and associated utility operations were required to be undertaken. Several meetings 

were held to keep local residents informed of the project progress and how it would impact on their 

day-to-day activities. There was also significant consultation undertaken with Bexley Council, the 

local water supply company (in respect of a water main diversion that was required) and the local 

gas company (in respect of existing pipes which lay within the pipe jacking pit). 

Other aspects of the project required sensitive handling and planning to minimise local and wider 

disruption given that the works would take place on busy London streets with traffic re-routing, road 

closures and limited working space. 

Crane movements on the site were to be 

kept to a minimum to avoid slewing 

pipes for example. 

To assist in minimising the effects of 

the work site itself on the local area both 

Day Time and Night Time compound 

set-ups were utilised. This was designed 

to ensure that during the evening whilst 

work continued underground, the surface 

area and therefore the impact of the site 

was smaller allowing as many residents 

as possible easy access into their 

properties. 

The project, which has been completed 

in various phases between the main 

contractor and A.E. Yates TS started in 

February 2008. With the second drive 

completed on October 21, 2008 the 

expected completion date for all the 

works is December 2008. 

Commenting on the project for A.E. 

Yates Andy Carnell, Project Manager 

said: “The relationship between all 

construction parties have been good 

throughout the project with a successful 

completion.” Website: 

www.aeyates.co.uk (for A.E Yates TS 

Ltd) or www.vmt-gmbh.de (for VMT) 

The Herrenknecht MH3 Open faced backacter unit completes 

holing on the first of the Sidcup drives. 



Insituform 











TT Group 







U Mole 







VMT GmbH 





Herrenknecht

pipe jacking, microtunnelling, & auger boring - nodig-construction.com

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